Here are some hints that will help you beat the Final Boss of Math & Magic:

* The first thing you should do is reduce its high Attack (303); it is better if none of your stats is a multiple of 3.
* The Dragon deals massive Magic damage on even turns, so use "Guard" or an item when it happens (having 2 Meats +500 or more is highly recommended).
* On the 3rd turn, reduce its HP to 998.
* Increase your Attack and reduce its Defence until your Physical attacks can hurt it.
* Don't forget to use "Whirlwind" every time it can highly reduce the Dragon's HP, it will save you a lot of turns.